Influences of biological and adoptive mothers' depression and antisocial behavior on adoptees' early behavior trajectories

Research clearly demonstrates that parents pass risk for depression and antisocial behavior on to their children. However, most research confounds genetic and environmental mechanisms by studying genetically related individuals. Furthermore, most studies focus on either depression or antisocial behavior in parents or children, despite evidence of co-occurrence and shared etiology, and few consider the early origins of these problems in childhood. We estimated the influence of biological and adoptive mothers' depression and antisocial behavior on growth in child externalizing and internalizing behaviors across early childhood using data from a prospective adoption study. Participants were 346 matched triads of physically healthy children (196 boys; 150 girls), biological mothers (BM), and adoptive mothers (AM). Latent growth curve models were estimated using AM reports of child internalizing and externalizing behaviors at ages 18, 27, and 54 months. Predictors of intercept (18 months) but not slope were identified. BM lifetime histories of major depressive disorder predicted child externalizing behaviors and BM antisocial behavior predicted child internalizing behavior. AM depressive symptoms and antisocial behavior were associated with both child outcomes. AM paths, but not BM paths were partially replicated using adopted fathers' reports of child outcomes. BM obstetric complications, prenatal depressive symptoms, and postnatal adoptive family contact with BM did not account for BM paths. This adoption study distinguished risks conferred by biological mothers' depression and antisocial behavior to children's behaviors from those associated with adoptive mothers' related symptoms. Future studies should examine gene-environment interplay to explain the emergence of serious problem trajectories in later childhood.